Stopcock to Lever Valve - Updated/Current Regs?

[SirLancelot]

For each of the units, could you recommend specific products/brands?

1) Main stop valve
2) A reliable Double check valve
3) Drain off

I am tempted to go Pegler DZR for (1)

Would appreciate any recommendations on (2) and (3).

Quality and reliablity would be my requirements.

 

[ATTQ]

Are check valves available full bore? If not I might not bother having one. The central heating being pressurized I can see the need and full flow to top that up isn't ever needed. But every other appliance is just water flowing in with no backwards pressure likely and even if say the washing machine filled up to the inlet, then it would have to freakishly coincide with a low pressure moment in the mains to be a risk of back flow into the mains.

 

[ATTQ]

I am tempted to go Pegler DZR for (1)

I'm glad i paid the extra few pounds for mine. That said they have a locking device which automatically engages if the handle is in the upright position, which i wanted so it is pull down for off as that seems most intuitive. 2 seconds to cut that off with an angle grinder

 

[Madrab]

Are check valves available full bore

Only ever seen single check valves @ full bore though they weren't approved I don't think but not doubles, though I dare say someone will make them - by the way they are constructed though it would end up quite a large valve.

freakishly coincide with a low pressure moment in the mains to be a risk of back flow into the mains.

Drops/fluctuations in the cold mains pressure happens all the time during the day and especially so at peak times, the amount of swing is usually location dependent - further away from district pumping etc. Even more so in say flats. It's all about protecting everyone. If you could see some of the stuff that some users have connected to their mains, you wouldn't want the risk of that backflowing up to where you brush your teeth.

Sadly not everyone follows the regs.

 

[ATTQ]

Only ever seen single check valves @ full bore though they weren't approved I don't think but not doubles, though I dare say someone will make them - by the way they are constructed though it would end up quite a large valve.


Drops/fluctuations in the cold mains pressure happens all the time during the day and especially so at peak times, the amount of swing is usually location dependent - further away from district pumping etc. Even more so in say flats. It's all about protecting everyone. If you could see some of the stuff that some users have connected to their mains, you wouldn't want the risk of that backflowing up to where you brush your teeth.

Sadly not everyone follows the regs.

Obvious potential solution would be go up to a 22mm valve and back to 15 straight after. Am i being silly to worry about this?

Another aspect is I've just received a pressure tester from Amazon and I'm rocking 5 bar mains pressure. Nothing has broken so far but is that high enough to warrant getting a PRV down to 3 bar? Not sure i'll have space for this series of lever valve, check valve, PRV and drain valve before it tees off to the boiler.

 

[Madrab]

As you are running 5bar, have you tested that dynamically? Set your gauge on say an outside tap (full flow) then run at least one or more outlets to see how the pressure drops, that will give you a dynamic reading. If you are still high >4bar then a PRV may be an idea as it will protect outlets within the property from undue stress from the increased pressure.

 

[ATTQ]

As you are running 5bar, have you tested that dynamically? Set your gauge on say an outside tap (full flow) then run at least one or more outlets to see how the pressure drops, that will give you a dynamic reading. If you are still high >4bar then a PRV may be an idea as it will protect outlets within the property from undue stress from the increased pressure.

It goes down to exactly 4 bar with the kitchen tap fully open and jumps to close to 9 bar when it is turned off with a noticeable judder through the pipes

the mains comes in via a black rubberized hose out of a poured concrete floor and I only have max 25cm of copper pipe before the tee to the boiler.

I'm changing all the pipework around there later anyway so can do what i want with it if really needed. With this high pressure I guess that makes it less likely to ever have negative or low enough pressure to really need the check valve (I'm surrounded by hills) so perhaps I should put the ball valve and the PRV at least if only room for 2 and some clips

 

[Madrab]

With this high pressure I guess that makes it less likely to ever have negative

Without a PRV, the pressure in the pipes in the property will be the same as the mains so any drop in the mains upstream of the supply pipe to your property will mean that there will always be backflow to the mains from your property and everyone else's too of course. If you do have a PRV fitted though, which would mean that the pressure within the property will be lower than the dynamic mains, then it will be less likely to be at a higher pressure on average than the mains, if there were any pressure fluctuations, therefore lower risk of backflow, if you see what I mean.

 

[SirLancelot]

Does anyone know of any units that come with the lever vlave and double check valve (possibly with drainoff) as a single unit. Because when you adda PRV, it's a lot of hardware on one run.

Especially if the MDPE pipe rises under a kitchen cupboard.

**UPDATE**

A)

Isolating, Pressure reducing, Double Check

Rather expensive - not sure why so

B)

Isolating, Double Check

Again, it seems rather expensive

Can anyone garner why these are priced so high?

 

[ATTQ]

All those have done is screw together the same bits in series as you'd do. Might save some length using screw fittings but might struggle to find screw on end and compression the other though I have seen some. To get them at domestic prices (rather than industrial) probably stuck with compression.

If its all compression fittings you can just use a small piece of copper between each one and it will be about the same length, then back to plastic both ends.

 

[Madrab]

A) - Rather expensive - not sure why so

Arrow Valves are high quality (HQ) components. It is very specific though and would say more designed for larger commercial/industrial applications. It would probably work well in a block of flats I guess but again that would probably be incorporated at build time rather than a modification after, so cost wouldn't be such a big factor. It's maybe a bit overkill for a DIY domestic retrofit. Would always take the separate double check, lever valve and DT-PRV if retrofitting.

B) - Again, it seems rather expensive

Again HQ bespoke components to do specific job, paying extra for the quality and the addition of the low loss check valves

Arrow valves are very very good and if cost isn't an issue then they are one of the top manufacturers for bespoke valves

If pressure and flow from the mains is high then the impact of a standard double check valve shouldn't be a real concern, especially if the valve is 22mm or even increased to 28mm.

 

[SirLancelot]

To bring this in for a quality landing,

Could those contributing to this thread recommend specific components from specific brands:

i) Lever Valve
ii) PRV
iii) Drain Off
iv) Double Check

For a domestic installation.

(assume that for each line components are available for diff sizes).

Basically, i'm asking if it was for your home or that of close family, which products from manufacturers would you select (& why)?

 

[ATTQ]

To bring this in for a quality landing,

Could those contributing to this thread recommend specific components from specific brands:

i) Lever Valve
ii) PRV
iii) Drain Off
iv) Double Check

For a domestic installation.

(assume that for each line components are available for diff sizes).

Basically, i'm asking if it was for your home or that of close family, which products from manufacturers would you select (& why)?

I'm happy with Pegler for all but the PRV I've just ordered from ebay 3 of Caleffi 533641H which are adjustable so i can tweek things for the house overall and can tweek each of the two mains fed mixer taps to bring them down to the same pressure as the hot comes from the boiler. Assuming that will be helpful? £20 each so thought might as well and can resell if dont use them in the end. Seems to be about the going rate for these on ebay.

My showers do struggle when i adjust the temperature. They are for 5 bar max so i'm right on the limit without knowing. Maybe will be happier somewhere in the middle of the range

 

[Madrab]

Really comes down to budget. Can't go far wrong with Arrow for all those components but they're not cheap. Pegler are also a good midrange choice.

One point though, it is advisable to get a Drop Tight (DT) PRV, avoids pressure bounce/spikes when the water is used especially when the differentials are significant

 

[SirLancelot]

Really comes down to budget. Can't go far wrong with Arrow for all those components but they're not cheap. Pegler are also a good midrange choice.

One point though, it is advisable to get a Drop Tight (DT) PRV, avoids pressure bounce/spikes when the water is used especially when the differentials are significant

Could you help expand on this more.

In what way does a DT PRV differ from an ordinary PRV.

Why is it worth looking at, and under what circumstances.

(The aim: to explore this topic to learn something new, and uncover different approaches).